It is difficult to assess the impact of cancer interventions on population level directly. Models may be appropriate tools for investigating different possible explanations for observed cancer incidence and mortality. This asks for models that are applicable in different populations. The microsimulation model MISCAN is applicable in different populations to evaluate the impact of breast cancer interventions. In the MISCAN model it is possible to specify demographic, epidemiological and economic information and also screening and other information such as risk factors, treatment practice and behavioral aspects. In this way insight can be gained concerning to what extent the observed trends in incidence and mortality of breast cancer can be explained by screening. Also the effects of other factors as changes in breast cancer awareness, differences in breast cancer risk by birth cohort, and changes in treatment will be studied. Furthermore, the MISCAN breast model can be used to predict effects of future cancer control strategies on population level. These results will be valuable for public health policy making and may have major impact on morbidity and mortality of breast cancer.